The major goal of my thesis project is to test the feasibility of creating a transgenic strain of the mosquito Aedes triseriatus which shows a reduced ability to transmit LaCrosse virus (LAC). LAC virus is a member of the California serogroup of bunyaviruses, and is a major cause of mosquito borne encephalitis in children. The project will involve the selection of neutralizing monoclonal antibodies to LAC, and the expression of selected single chain antibody fragments in the mosquito using a double subgenomic Sindbis virus expression system. The Sindbis recombinants will be evaluated to determine if the expressed antibody fragment is capable of inhibiting productive viral infection or blocking the transmission of LAC. A secondary aim of the project is to design a transformation system for the bacterial endosymbiont Wolbachia. Wolbachia is associated with the phenomenon of cytoplasmic incompatibility. This bacteria could be used to introduce and maintain the desired refractory genes in insect populations.